Sparking plug for internal-combustion engines



c. M. E. L. MONNIER. SPARKING PLUG FOR tNTERNAL COMBUSTION ENGINES.

APPLICATION FILED JULY 29, l9l9.

Patented: Mar. 23, 1920.

Fig. A

Fig.3.

WWW 7- [131 ff Ma /11a Ernest? [dais Mannie r" tication.

l rance, have invented new and'useiul llniprovements in Sparking Plugsfor internal- Comhustlon Engines, WhlCh mprovement-s are fully setfol-thin the following speei Sparking plugs for internal combustionengines'l requently get out of Working order in a very short time whichis due partly to the obstruction or fouling of the contacts and partlyto theexpansion oi" the centred terminal, producingelongation resultingin leakages and heating and consequently in. stoppages in Working; ofthe plug.

- This invention relates" to a construction oi" sparking plug 'Whereinthe aforesaid drawbacks ere'aroidedby etlecting the ignition. of thegaseous mixture by means of a disruptive spurt. Moreover the construction of this plup; is such as to permit it to; be entirely taken topieces.

In the "accompanying drawings which illustrate one embodiment of theinven tion j r l igure 1 is a eeotional elevation of the plum Fig. 2 isu side View of the same.

Figs. 3 and 4 are a sectional elevation and hide viewpi a modification,res 'ieetively.

The plug is essentially constituted by a metal body or nipple e providedwith cooling ribs and in Whichie mounted an insu later consisting'ot'three parts 5, c, d, Which are held in position bymeans of asocketmember having an external thread en raging an internal thread in thebody (a. l W0 thumb nuts f, f screwed on the socket 6 lock the latter inposition.

A central terminal or electrode comprising two parts It, is arrangedcentrally and longitudinally of the insulator. The lower part 7 issupported in the lower insulator n'leinher Z by a shoulder 01'? collarand the upper part I: is secured in. the upper insulater member (Zhymeuns of a shoulder or collar l and the usualai'ran -ement otwusln ere,nut and lock-nut The internal ends of both parts of the electrode areoppositely arranged in a recess m provided in the middle insulator part0.

Packing rings of any suitable materials such as aluminium, asbestos,&c., are prolll llll tlpecificetton of Letters lietent. I Pattgt tp rllllile lr vided at n 0, 79., Q in order to other terininnl. shown in thedin mg"... i. one hat into.

Application filed July 5249,1919. Serial lilo. 31.4l,?t81.

sired tightnessot the plug.

secure the do i The upper and lower insnletor mrnnbere (l 'and (5 theyalso he made oi any suit/elite niuteriuls such in; quarto, inicu,porcelain, etc.,' but the middle insulutor inen'll :3 must be made ot atinnspurent inuterin i, prefer ahlv oi qunzrta.

- ln operetion, first direct spark produred between the inner ends ofthe trode members in. the rec m, which 'lorine a hnreti chamber. 'lhhigh current time produced rle to a dis-- ruptive epitrlt at thedowerend' ot the electrode member g, e... in the mnnlnistion ehe-inhe'r. "Onaccount til it a particular teaturos ol l'iigh frequencyalternatincurren e.

said end oi the central terminal and s be tsel'h should ingtornied bythe plug: body I 'even the terminals be fouled. a

It W1ll be understood moreover thettne expansion of the lower party 0tthe con-- tral electrode does not affect the upper part it so that theplug-is not liable to become loosened or out of order.

Aplurality of windows "1* (for instanue tour in number) are provided in.the socket at u level with the hnrstii'lg cl amber *1. so

- that on eeeount of the transparence oi? the middle insulator ineniheithe spark pro duced in said chamber may easily be seen. "lhis permits ofobserving" ,ut any moment the correct Working: of the pines inoi'mted onan engine and to find easily, Without any dismount-inn, any plug; WhiehInn-v not Worlr. satisfactorily. It will be understood th t thearrangement herein described they be varied as to details itl'ioutdeparting from the spirit oi the invention.

Such a modification is shown by Way oil" example in sectional elevationin Fig. 3 and side view in Fig 1. As shown the plug; body or nipple a;is modified in such a men ner as to permit easy access to the plug incases Where the same is arranged in the hollow velve-covers connnonlyused in automobile engine construction.

Besides the body a is provided internally and concentrically of thesocket e With an annular chamber 8 communicating with the atmosphere bymeans oi Windows 25 provided in the body a at a level with the Windows1' frequencyin the socket e, on the one hand, and by i means of aplurality of holes u bored in the socket, on the other hand. Aircirculation is thus provided and assists in cooling'the plug. Besidesthese holes may serve to effeet the screwing and locking of the socket ewhen mounting the plug.

It will be easily understood that all the members of which the plug iscomposed may .beeasily dismounted and remounted.

What I claim is:

1. In aspark plug, the combination of'a hollow metal body; a hollowsocket mounted in said bodyand formed with a sight opening which isvisible from the outside of .the

' plug; an insulating element composed of upper,- intermediate and lowermembers mounted 1n superposed relation within said socket, and formedwith registering axial passages, the intermediate member being,

constructed of transparent material and the passages inthat member andin the lower hollow metal body formed with an internal annular aircliamber and with a plurality of openings extending laterally lroni saidchamber and leading through the outer face of the body; a.' hollo'wsocket mounted in said base and formed wlth lateral sight openings whichaline with the lateral openings in said body and also formed withvertical openings at its upper end which communicate with said airchamber; an insu lating element mounted in said socket and having itscentral portion located opposite said lateral openings and constructedof transparent material, said insulating element being formed'with anaxial passage which opens therethrough at opposite ends; and anelectrode comprising upper and lower axially-alining members mounted insaid passage, the confronting ends of the electrode members beingdisposed within the transparent portion of the insulating,

element at a point opposite said lateral open- "ingsso. as'tobe visiblethrough the same.

3. In a spark plug, the combination of a hollow metal body formed withan internal annular air chamber and with a plurality of openingsextending laterally from said chamber and leading through the outer faceof the body; a hollow socket mounted in said base and formed withlateral sight openings which aline with the lateral openings in saidbody and also formed with vertical openings at its upper end whichcommunicate w1th said air chamber; an insulating element composed, ofupper, intermediate and lower members mounted in superposed relationwithin said socket and formed with registering axial passages, theintermediate memberbeing constructed of transparent material and thepassages in that member and in the lower member having enlargedportions, the enlargement in the intermediate member being locatedopposite said alining lateral openings; and an electrode comprisingupper and, lower members mounted in said passages'ainl having supporting shoulders disposed within the enlargements thereof, theconfronting ends of the electrode members projecting into theenlargement in the intermediate chamber and spaced from each othertherein to provide a spark gap which is visible thrtnlgh said lateralopenings.

Intestimony whereof I. have signed this specification in the presence oftwo subscribing witnesses.

CHARLES MARIE ERNEST LOUIS MlNNlllll.

\Vitnesses l Ins n1 Loomrr, ll'rinnnn Siunn'r.

